Ob leeg ketones thiab esters yog ob ntawm cov pab pawg tseem ceeb tshaj plaws hauv cov tshuaj lom neeg. Lawv muaj nyob rau hauv ntau yam ntawm cov organic tebchaw thiab ua lub luag haujlwm tseem ceeb hauv ntau cov txheej txheem lom neeg thiab tshuaj lom neeg. Txawm tias lawv zoo sib xws, lawv cov yam ntxwv thiab kev coj cwj pwm txawv heev. Cia peb tshawb nrhiav seb ketones thiab esters yog dab tsi, lawv txawv li cas, lawv zoo li cas, thiab lawv txhais li cas hauv chemistry thiab biology.
Ketones yog ib chav kawm ntawm cov organic tebchaw uas muaj cov pab pawg carbonyl functional (C = O) nyob nruab nrab ntawm cov molecule. Ketones muaj ob pawg alkyl lossis aryl txuas nrog cov carbonyl carbon. Qhov yooj yim tshaj plaws ntawm cov no yog acetone, uas muaj cov mis (CH3) 2CO. Lawv yog tsim los ntawm kev rhuav tshem cov rog hauv lub cev. Kuj tseem hu ua ketone lub cev, ketones yog cov tshuaj tsim tawm thaum koj lub cev pib zom cov rog tsis yog carbohydrates rau lub zog.
Ketones yog tsim los ntawm fatty acids nyob rau hauv daim siab thiab tso tawm mus rau hauv cov hlab ntsha, uas lawv yuav siv tau raws li ib tug lub zog qhov chaw rau lub cev lub hlwb thiab lub cev. Thaum lub cev nyob hauv ketosis, nws tso siab rau ketones ua nws cov roj tseem ceeb, tsis yog cov piam thaj, uas yog vim li cas cov zaub mov ketogenic tau nrov heev hauv xyoo tas los no. Txawm li cas los xij, ketones tsis tsuas yog tsim thaum yoo mov lossis noj ketogenic. Lawv tuaj yeem tsim tau thaum lub cev muaj kev ntxhov siab, xws li thaum lub sijhawm ua haujlwm hnyav, lossis thaum tsis muaj insulin hauv lub cev, uas tuaj yeem tshwm sim rau cov neeg mob ntshav qab zib.
Peb ketones yog tsim thaum lub sij hawm ketosis: acetone, acetoacetate, thiab beta-hydroxybutyrate (BHB). Ntawm lawv, acetone yog ib qho ketone uas tawm hauv lub cev los ntawm kev ua pa, uas ua rau lub cev tsw qab los yog tsw qab, feem ntau hu ua "keto pa". Qhov no tuaj yeem yog qhov qhia tias koj lub cev tau nkag mus rau hauv lub xeev ntawm ketosis. Acetoacetate, lwm ketone, yog tsim nyob rau hauv daim siab thiab siv los ntawm lub cev hlwb rau lub zog. Txawm li cas los xij, nws kuj hloov mus rau BHB, feem ntau hom ketone hauv cov ntshav thaum ketosis. BHB tuaj yeem yooj yim hla cov ntshav-hlwb teeb meem, yog li ua kom lub hlwb muaj zog thiab tuaj yeem txhim kho lub hlwb kom pom tseeb thiab ua kom pom tseeb.
Esters yog cov organic sib txuas nrog RCOOR 'kev ua haujlwm, qhov twg R thiab R' yog ib pawg organic. Esters yog tsim thaum carboxylic acids thiab alcohols react nyob rau hauv acidic tej yam kev mob thiab tshem tawm ib tug molecule ntawm dej. Lawv feem ntau pom muaj nyob rau hauv cov roj yam tseem ceeb thiab ntau cov txiv hmab txiv ntoo. Piv txwv li, lub aroma ntawm txiv tsawb siav los ntawm ester hu ua isoamyl acetate.Esters muaj cov khoom tshwj xeeb uas ua rau lawv muaj txiaj ntsig hauv ntau yam lag luam.
1. Cov tshuaj tsw qab
Ib qho ntawm feem ntau siv esters yog nyob rau hauv fragrances thiab perfumes vim lawv qab zib, fruity thiab qab ntxiag tsw, thiab lawv kuj pab txhim khu lub zuag qhia tag nrho cov ntxhiab ntawm ib yam khoom, ua rau nws txaus siab rau cov neeg siv.
2. Zaub mov tsw
Cov qauv tshuaj tshwj xeeb ntawm esters tso cai rau lawv faib cov txiv hmab txiv ntoo thiab cov paj ntoo, yog li esters kuj tau siv hauv kev lag luam zaub mov, tshwj xeeb tshaj yog nyob rau hauv flavorings. Nws yog feem ntau nyob rau hauv ntau yam khoom noj xws li confectionery, ci khoom thiab dej haus. Nyob rau hauv lub neej txhua hnub, esters tau siv nyob rau hauv zus tau tej cov khoom xyaw thiab tau dhau los ua cov khoom xyaw hauv ntau yam khoom noj.
3. Yas
Raws li plasticizers, esters ua plastics hloov tau yooj yim thiab ruaj khov. Yog li esters yog siv los tsim ntau yam yas, thiab lawv kuj pab tiv thaiv cov yas los ntawm nkig dhau sijhawm. Qhov no yog qhov tseem ceeb rau cov khoom siv ruaj khov xws li cov khoom siv tsheb lossis cov khoom siv kho mob.
4. Cov kuab tshuaj
Vim tias esters tuaj yeem yaj cov organic xws li roj, resins thiab rog. Yog li ntawd, esters muaj txiaj ntsig zoo hauv ntau qhov kev lag luam ua cov kuab tshuaj rau dissolving lwm yam khoom. Esters yog cov kuab tshuaj zoo, uas ua rau lawv muaj txiaj ntsig zoo hauv kev tsim cov xim, varnishes thiab nplaum.
Los ntawm kev sib piv ketones thiab esters, peb tuaj yeem pom tias qhov sib txawv ntawm ketones thiab esters feem ntau yog hauv cov hauv qab no:
1. Qhov sib txawv tseem ceeb ntawm ketones thiab esters feem ntau yog nyob rau hauv cov qauv tshuaj. Cov pab pawg carbonyl ntawm ketones nyob rau hauv nruab nrab ntawm cov pa roj carbon saw, thaum cov carbonyl pawg ntawm esters nyob rau hauv qhov kawg ntawm cov carbon saw. Qhov sib txawv ntawm cov qauv no ua rau muaj qhov sib txawv ntawm lawv lub cev thiab tshuaj lom neeg.
●Ketones yog cov organic tebchaw uas muaj cov pab pawg carbonyl uas muaj cov pa oxygen atom ob npaug rau cov pa roj carbon atom nyob hauv nruab nrab ntawm cov saw hlau. Lawv cov qauv tshuaj yog R-CO-R', qhov twg R thiab R' yog alkyl lossis aryl. Ketones yog tsim los ntawm oxidation ntawm cov cawv thib ob los yog cleavage ntawm carboxylic acids. Lawv kuj tau txais keto-enol tautomerism, uas txhais tau tias lawv tuaj yeem muaj nyob rau hauv ob qho tib si ketone thiab enol cov ntaub ntawv. Ketones feem ntau yog siv los tsim cov kuab tshuaj, cov ntaub ntawv polymer thiab tshuaj.
●Esters yog cov organic tebchaw uas muaj cov pab pawg carbonyl kawg ntawm cov saw hlau thiab ib pawg R txuas nrog cov pa atom. Lawv cov qauv tshuaj yog R-COOR ', qhov twg R thiab R' yog alkyl lossis aryl. Esters yog tsim los ntawm cov tshuaj tiv thaiv ntawm carboxylic acids nrog cawv nyob rau hauv lub xub ntiag ntawm ib tug catalyst. Lawv muaj ib tug fruity tsw thiab feem ntau yog siv nyob rau hauv zus tau tej cov perfumes, essences thiab plasticizers.
2.Qhov pom tseeb tshaj qhov sib txawv ntawm ketones thiab esters yog lawv cov ntsiab lus kub. Qhov kub ntawm ketones siab dua li ntawm esters vim tias lawv muaj zog intermolecular zog. Cov pab pawg carbonyl hauv ketone tuaj yeem tsim hydrogen bonds nrog ketone molecules nyob ze, ua rau muaj zog intermolecular rog. Nyob rau hauv sib piv, esters muaj zog intermolecular zog vim tsis muaj peev xwm ntawm cov pa atoms nyob rau hauv lub R pab pawg neeg los tsim hydrogen bonds nrog ester molecules nyob ze.
3.Tsis tas li ntawd, qhov reactivity ntawm ketones thiab esters txawv. Vim tias muaj ob pawg alkyl lossis aryl ntawm ob sab ntawm pawg carbonyl, ketones ntau dua li cov esters. Cov pab pawg no tuaj yeem pub cov khoom siv hluav taws xob rau carbonyl, ua rau nws yooj yim dua rau kev tawm tsam nucleophilic. Hauv qhov sib piv, esters tsis tshua muaj tshwm sim vim muaj cov alkyl lossis aryl pawg ntawm cov pa atom. Cov pab pawg no tuaj yeem pub cov khoom siv hluav taws xob rau oxygen atom, ua rau nws tsis tshua muaj kev cuam tshuam rau nucleophilic nres.
4. Vim muaj cov qauv sib txawv, cov ntsiab lus kub kub thiab kev ua haujlwm ntawm ketones thiab esters, qhov sib txawv ntawm lawv siv tau txiav txim siab. Ketones feem ntau yog siv rau hauv kev tsim cov kuab tshuaj, cov khoom siv polymer thiab tshuaj, thaum esters feem ntau siv rau hauv kev tsim cov tshuaj tsw qab, flavors thiab plasticizers. Ketones kuj tseem siv los ua roj ntxiv hauv cov roj av, thaum esters siv los ua cov roj nplua nyeem hauv tshuab.
Peb twb paub cov ntsiab lus ntawm ketones thiab esters, yog li qhov txawv ntawm ketones, esters thiab ether yog dab tsi?
Ua ntej tshaj plaws, peb yuav tsum paub tias ether yog dab tsi? ether muaj cov pa oxygen atom txuas rau ob lub atoms carbon. Lawv yog ib tug compound paub txog nws cov khoom narcotic. ether feem ntau tsis muaj xim, tsawg dua li dej, thiab yog cov kuab tshuaj zoo rau lwm cov organic tebchaw xws li roj thiab roj. Lawv kuj tau siv los ua cov khoom siv roj ntxiv hauv cov roj av los txhim kho kev ua haujlwm ntawm lub cav.
Tom qab nkag siab txog cov qauv tshuaj thiab kev siv ntawm peb qhov no, peb tuaj yeem paub meej tias qhov sib txawv ntawm ketones, esters thiab ether suav nrog ob yam hauv qab no:
1. Ib qho ntawm qhov sib txawv tseem ceeb tshaj plaws uas peb tuaj yeem pom ntawm ketones, esters, thiab ether yog lawv pawg ua haujlwm. Ketones muaj cov pab pawg carbonyl, esters muaj ester-COO- kev sib txuas, thiab ether tsis muaj cov pab pawg ua haujlwm. Ketones thiab esters qhia qee qhov zoo sib xws hauv cov khoom siv tshuaj. Ob lub tebchaw yog polar thiab tuaj yeem tsim hydrogen bonds nrog lwm cov molecules, tab sis cov hydrogen bonds hauv ketones muaj zog dua li cov hauv esters, ua rau muaj qhov kub siab dua.
2.Lwm qhov sib txawv tseem ceeb yog qhov peb muaj kev siv sib txawv
(1)Ib qho ntawm feem ntau siv ntawm ketones yog raws li ib tug hnyav rau resins, waxes, thiab roj. Lawv kuj tseem siv rau hauv kev tsim cov tshuaj zoo, tshuaj thiab agrochemicals. Ketones xws li acetone yog siv los tsim cov yas, fibers thiab xim.
(2)Esters feem ntau siv rau hauv cov khoom noj thiab tshuaj pleev ib ce rau lawv cov aroma thiab tsw. Lawv kuj tseem siv los ua cov kuab tshuaj rau inks, varnishes thiab polymers. Esters kuj tseem siv rau hauv kev tsim cov resins, plasticizers thiab surfactants.
(3)ether muaj ntau yam kev siv vim lawv cov khoom tshwj xeeb. Lawv siv los ua cov kuab tshuaj, tshuaj loog thiab surfactants, thiab lwm yam. Hauv kev lag luam ua liaj ua teb, lawv tau siv los ua fumigants los tiv thaiv cov qoob loo khaws cia los ntawm kab tsuag thiab kab mob fungal. ether kuj tseem siv rau hauv kev tsim cov epoxy resins, adhesives thiab cladding cov ntaub ntawv.
Ketones thiab esters muaj ntau daim ntawv thov nyob rau hauv cov organic chemistry thiab yog lub tsev thaiv ntawm ntau cov txheej txheem kev lag luam. Piv txwv li, ketones yog siv los ua cov kuab tshuaj, hauv kev tsim tshuaj thiab polymers. Esters, ntawm qhov tod tes, yog siv hauv kev lag luam naj hoom thiab tshuaj pleev ib ce, ua cov tshuaj tsw qab hauv kev lag luam zaub mov, ua kuab tshuaj, thiab tseem nyob rau hauv cov xim thiab coatings.
Post lub sij hawm: Jun-14-2023
